Dealcoholated red wine induces autophagic and apoptotic cell death in an osteosarcoma cell line

Until recently, the supposed preventive effects of red wine against cardiovascular diseases, the so-called "French Paradox", has been associated to its antioxidant properties. The interest in the anticancer capacity of polyphenols present in red wine strongly increased consequently to the enormous number of studies on resveratrol. In this study, using lyophilized red wine, we present evidence that its anticancer effect in a cellular model is mediated by apoptotic and autophagic cell death. Using a human osteosarcoma cell line, U2Os, we found that the lyophilized red wine was cytotoxic in a dose-dependent manner with a maximum effect in the range of 100-200 μg/ml equivalents of gallic acid. A mixed phenotype of types I/II cell death was evidenced by means of specific assays following treatment of U2Os with lyophilized red wine, e.g., autophagy and apoptosis. We found that cell death induced by lyophilized red wine proceeded through a mechanism independent from its anti-oxidant activity and involving the inhibition of PI3K/Akt kinase signaling. Considering the relative low concentration of each single bioactive compound in lyophilized red wine, our study suggests the activation of synergistic mechanism able to inhibit growth in malignant cells.

Indoor air pollution and airway disease

Scientific interest in indoor pollution has been increasing since the second half of the 1980s. Growing scientific evidence has shown that because people generally spend the majority of their time indoors, indoor pollution plays a significant role in affecting health and is thus an important health issue. Indoor environments include dwellings, workplaces, schools and day care centres, bars, discotheques and vehicles. Common indoor pollutants are environmental tobacco smoke, particulate matter, nitrogen dioxide, carbon monoxide, volatile organic compounds and biological allergens. In developing countries, relevant sources of indoor pollution include biomass and coal burning for cooking and heating. Concentrations of these pollutants can be many times higher indoors than outdoors. Indoor air pollution may increase the risk of irritation phenomena, allergic sensitisation, acute and chronic respiratory disorders and lung function impairment. Recent conservative estimates have shown that 1.5-2 million deaths per year worldwide could be attributed to indoor air pollution. Approximately 1 million of these deaths occur in children aged under 5 years due to acute respiratory infections, and significant proportions of deaths occur due to chronic obstructive pulmonary disease and lung cancer in women. Today, indoor air pollution ranks tenth among preventable risk factors contributing to the global burden of disease. Further research is necessary to better evaluate the respiratory health effects of indoor pollution and to implement protective programmes for public health.

[Longitudinal study on osteoarthritis and bone metabolism]

OBJECTIVE

The relationship between Osteoarthritis (OA) and Osteoporosis (OP) is not well defined due to lacking in longitudinal data, mainly regarding correlations between biochemical factors and OA incidence. Aim of this paper was to investigate the predictive value for OA incidence of bone mass variations and of selected biochemical markers in healthy women participating in a population-based longitudinal study carried out in Naples (Italy).

SUBJECTS AND METHODS

High completion rate (85.2%) and statistically adequate sample size were obtained: 139 women (45 to 79 years of age) were examined and follow up visit was performed after two years (24+/-2 months), following the same protocol. Patients underwent medical examination, questionnaire, anthropometric measurements, blood sampling and urine collection. Bone mineral density (BMD) measurement was performed by dual energy X-ray absorptiometry (DEXA) at the lumbar spine (L1-L4) and femoral neck. Radiographs of dorsal and lumbar spine in lateral view were performed at basal and at 24 months visits; a team of three experts scored radiographs using Kellgren and Lawrence grading.

RESULTS

The score was calculated for two individual radiographic features (narrowing of the joint space, presence of osteophytes) and as a global score. Results show a relevant percentage, 23% up, of subjects presenting both OA and OP. In the cross-sectional study the presence of osteophytosis correlates with anthropometric variables and PTH levels. In the longitudinal study results show a correlation between serum vitamin D and delta score for osteophytosis (beta=0.02 p<0.05).

CONCLUSIONS

Data obtained outline the importance of further studies on the pathogenetic link between OA and bone metabolism.

Longitudinal changes of body mass index, spirometry and diffusion in a general population

The aim of this study was to evaluate the effects of body mass index (BMI) changes over an 8-yr follow-up, on longitudinal changes of vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and carbon monoxide diffusing capacity of the lung (DL,CO) indices in a general population sample of North Italy. To avoid including weight changes possibly related to physical growth, only the 1,426 adults (>24 yrs, 46% males) with complete follow-up were selected. Median linear regression models were applied to estimate the medians of change (computed as follow-up minus baseline values) of VC, FVC, FEV1 and DL,CO indices, as functions of changes of BMI over the follow-up period, separately by sex, after considering several potential confounders and effect modifiers. The extent of lung function loss tended to be higher among those who, at baseline, reported greater BMI values. Males experienced larger losses than females (20 and 16 mL FEV1 median reduction for a BMI unit increase in males and females, respectively). Conversely, longitudinal changes of BMI caused a slight and nonsignificant increase in DL,CO values in both sexes. Over an 8-yr follow-up, the detrimental effect of gaining weight might be reversible for many adults as most of those who reduced their body mass index values also increased their lung function. Overweight patients with ventilatory impairment should be routinely encouraged to lose weight for improving their lung function.

Epidemiology of chronic obstructive pulmonary disease (COPD)

Chronic Obstructive Pulmonary Disease (COPD) is one of the leading causes of morbidity and mortality in the industrialized and the developing countries. During 1997, COPD has been estimated to be the number four cause of death after cardiovascular diseases, tumors and cerebrovascular diseases in the United States. In 2020 COPD will probably become the third leading cause of death all over the world, following the trend of increasing prevalence of lung cancer. The impact of this respiratory disease worldwide is expected to increase with a heavy economic burden on individuals and society. In the United States direct and indirect costs of COPD were estimated at about USD24 billion in 1993. Unfortunately, there are few data on health-care utilization despite the great interest in COPD among researchers. As all chronic diseases, the prevalence of COPD is strongly associated with age. Data collected in a general population sample (living in Italy) showed a progressive increase of the prevalence of chronic bronchitis and emphysema with age, both in males and in females. COPD is determined by the action of a number of various risk factors either singly or interacting among themselves in a synergistic way. Among these, the most important is cigarette smoking, ranking at the first level for developing chronic bronchitis and emphysema. Also air pollution and some occupational exposures represent risks for developing COPD. Many epidemiological studies have indicated an association between the prevalence of chronic bronchitis and a low socioeconomic status. Furthermore, in the etiology of COPD we must consider endogenous risk factors such as gender, genetic features, presence of respiratory troubles in childhood, and family history. To date, epidemiologic studies have been of great importance for the characterization of the disease at a population level, indicating possible causes and assessing its impact on the individual and on society as a whole. Unfortunately, international standards for the diagnosis of COPD are lacking, which complicates the organization of appropriate epidemiological surveys.

Intramuscular clodronate in nonresponders to oral alendronate therapy for osteoporosis

OBJECTIVE

Oral alendronate is effective in increasing bone mineral density (BMD) and in reducing fracture incidence. However, a large proportion of patients under treatment do not show significant changes in BMD, or even bone loss. Incorrect administration, low intestinal absorption, and poor compliance are among factors that may account for this effect. In this subgroup of patients we evaluated whether intramuscular (im) clodronate increased the number of responders.

METHODS

Using an open case-control design we studied 60 postmenopausal osteoporotic women (mean age 58.9 years +/- 4.8 SD) after one year of therapy with oral alendronate who had an increase in BMD that was lower than the in vivo densitometry measurement error (2%). Subjects were divided into 2 groups: the first continued aledronate treatment (AL group); the second began weekly im injections of clodronate 100 mg (CL group). BMD measurements were performed at the right femoral neck by the same operator, using dual energy x-ray absorptiometry.

RESULTS

After 12 months of therapy the prevalence of responders (increase in BMD > 2%) was 40% in the AL group and 66% in the CL group (prevalence rate ratio = 1.65; 95% CI 1.25-2.04). The treatment group was the only variable that showed a significant correlation with being a responder (beta = 1.13; p = 0.03), as analyzed by multiple logistic regression to account for the effect of confounding factors. In the CL group the difference in the mean value of BMD between time T0 and time T+12 was greater than in the AL group, but did not reach statistical significance. The mean percentage variation of BMD was significantly greater in the CL group (+3.21%) compared to the AL group (+0.98%) (p < 0.001, t test) (f value = 8.4; p < 0.01, by multiple linear regression analysis using the same covariates).

CONCLUSION

Treatment with weekly intramuscular injection of clodronate in nonresponders to oral alendronate showed a higher number of subjects with a significant increase in BMD, compared to continuation of therapy with alendronate.

Endogenous tissue factor pathway inhibitor modulates thrombus formation in an in vivo model of rabbit carotid artery stenosis and endothelial injury

BACKGROUND

Tissue factor pathway inhibitor (TFPI) is the sole known inhibitor of the extrinsic coagulation pathway of physiological importance; however, its role in modulating thrombosis in vivo is still unclear.

METHODS AND RESULTS

Intravascular thrombosis was initiated by placing an external constrictor around endothelially injured rabbit carotid arteries (n=10). Carotid blood flow velocity was measured by a Doppler flow probe. After placement of the constrictor, cyclic flow reductions (CFRs), due to recurrent thrombosis, developed at the site of stenosis. Transstenotic TFPI plasma activity was measured in blood samples before induction of CFRs and after 30, 60, and 180 minutes of CFRs. TFPI plasma activity distal to the site of thrombosis was significantly lower than the corresponding proximal values at 30, 60, and 180 minutes of CFRs. In addition, a progressive decrease in TFPI plasma activity was observed in both the proximal and the distal samples, indicating consumption of TFPI during thrombus formation. In 10 additional rabbits, CFRs were abolished by administration of aspirin (10 mg/kg). In the animals in which aspirin abolished CFRs, endogenous TFPI was depleted by a bolus of a polyclonal antibody against rabbit TFPI, and the effects on restoration of CFRs were monitored. In 5 of 6 animals in which aspirin abolished CFRs, depletion of endogenous TFPI activity caused full restoration of CFRs.

CONCLUSIONS

The data of the present study support the involvement of endogenous TFPI in the process of thrombus formation in vivo and its active role in modulating arterial thrombosis.

Recombinant human, active site-blocked factor VIIa reduces infarct size and no-reflow phenomenon in rabbits

Oxygen free radicals induce de novo synthesis of tissue factor (TF), the initiator of the extrinsic pathway of coagulation, within the coronary vasculature during postischemic reperfusion. In the present study we wanted to assess whether TF expression might cause myocardial injury during postischemic reperfusion. Anesthetized rabbits underwent 30 min of coronary occlusion followed by 5.5 h of reperfusion. At reperfusion the animals received 1) saline (n = 8), 2) human recombinant, active site-blocked activated factor VII (FVIIai, 1 mg/kg, n = 8), or 3) human recombinant activated FVII (FVIIa, 1 mg/kg, n = 8). FVIIai binds to TF as native FVII, but with the active site blocked it inhibits TF procoagulant activity. The area at risk of infarction (AR), the infarct size (IS), and the no-reflow area (NR) were determined at the end of the experiment. FVIIai resulted in a significant reduction in IS and NR with respect to control animals (28.1 +/- 11.3 and 11.1 +/- 6.1% of AR vs. 59.8 +/- 12.8 and 24.4 +/- 2.7% of AR, respectively, P < 0.01), whereas FVIIa resulted in a significant increase in IS and NR to 80.1 +/- 13. 1 and 61.9 +/- 13.8% of AR, respectively (P < 0.01). In conclusion, TF-mediated activation of the extrinsic coagulation pathway makes an important contribution to myocardial injury during postischemic reperfusion.

Antithrombotic effects of recombinant human, active site-blocked factor VIIa in a rabbit model of recurrent arterial thrombosis

The extrinsic coagulation pathway is activated when circulating factor VII (FVII) gains access to tissue factor (TF) exposed as a consequence of vascular injury. Increasing evidence indicates that this TF-dependent activation of the coagulation plays an important role in the pathophysiology of intravascular thrombus formation. In the present study, we tested the effects of recombinant human, active site-blocked activated FVII (FVIIai) in a rabbit model of carotid artery thrombosis. Cyclic flow variations (CFVs), due to recurrent thrombus formation, were obtained in stenotic rabbit carotid arteries with endothelial injury. Carotid blood flow velocity was measured by a Doppler flow probe. After 30 minutes of CFVs, the animals received FVIIai (100 microg x kg(-1) x min(-1) intracarotid infusion for 10 minutes, n=9). If CFVs were abolished, animals were followed for 30 additional minutes, after which recombinant human activated FVII (FVIIa) was infused into the carotid artery (100 microg x kg(-1) x min(-1) for 10 minutes) to determine whether FVIIai could be displaced from TF by FVIIa, thus restoring CFVs. To establish the duration of action of FVIIai, an additional group of animals received FVIIai at the same dose as above, and after CFVs were inhibited, they were followed until CFVs were restored or for up to 6 hours. To determine whether CFVs could be restored by epinephrine after their abolition with FVIIai, increasing doses of epinephrine were administered to a third group of 6 animals. FVIIai abolished CFVs in 8 of 9 rabbits (P<.01). This effect was reversible, as FVIIa administration restored CFVs in all animals. Prothrombin times and activated partial thromboplastin times did not change significantly throughout the study. One single 10-minute infusion exerted complete antithrombotic effects for at least 6 hours, despite the fact that at this time point, plasma FVIIai levels were well below threshold concentrations. Epinephrine restored CFVs in 3 of 6 animals in which CFVs were inhibited by FVIIai. FVIIai exerts potent antithrombotic effects in this model; these effects were prolonged even after FVIIai was almost completely cleared from the circulation, probably as a result of the tight binding of FVIIai to TF. Thus, FVIIai might represent an antithrombotic substance of potential interest.

[Modifications in diagnosis and therapy of osteoporosis after bone densitometry]

The cost-benefit ratio of diagnostic procedures has become a major problem: in particular, the expense of computerized bone mineral densitometry for osteoporosis diagnosis has brought this issue to public attention. To avoid a procedure considered costly, non-specialists often rely on standard radiography alone for diagnosis. In this study, we evaluated the percent of cases in which densitometry modified diagnosis and therapy based solely on radiographic findings. Over a 10-month period, we recruited 133 consecutive post-menopausal patients (average age 58.3 years, average time since menopause 12 years) who had never undergone densitometry. Bone density at the lumbar (L1-L4) or femoral (non-dominant) level was measured with dual energy X-ray absorptiometry. The average time between densitometry and the last radiographic examination was 13.6 months. Ninety-one patients (68.4%) had a change in diagnosis following densitometry. In 42 cases (31.6%), the previous diagnosis remained unchanged (prevalence ratio 2.2; 95% confidence interval 1.6 to 2.7). Therapy was changed in 75.2% of the cases (100 patients) and remained the same in 24.8% (33 patients; prevalence ratio 3.0; 95% confidence interval 2.3 to 3.7). Our data underscore the importance of densitometry in yielding quantitative data that are utilizable during follow-up and able to support osteoporosis diagnosis and therapy.

Oxygen radicals can induce preconditioning in rabbit hearts

Indirect evidence suggests that oxygen radicals may contribute to ischemic preconditioning. We directly investigated whether exposure to oxygen radicals per se, in the absence of ischemia, could reproduce the beneficial effects of ischemic preconditioning on infarct size and on postischemic contractile dysfunction. In one branch of the study, isolated rabbit hearts underwent 30 minutes of total global ischemia and 45 minutes of reperfusion (n=6, control group). A second group, before ischemia/reperfusion, was exposed for 5 minutes to a low flux of oxygen radicals generated by purine/xanthine oxidase (P/XO), followed by a 15-minute washout (n=6). Oxygen radical pretreatment significantly improved postischemic recovery of contractile function. We then investigated in another branch of the study whether this preconditioning effect would also reduce infarct size and whether it was mediated by protein kinase C activation. Control hearts were subjected to coronary artery occlusion for 30 minutes, followed by 2.5 hours of reperfusion (n=6). A second group, before coronary occlusion, was exposed to oxygen radicals and washout as described (n=8). A third group was subjected to oxygen radical infusion, but an inhibitor of protein kinase C (polymyxin B, 50 micromol/L) was administered throughout subsequent ischemia (n=7). A fourth group was exposed to oxygen radicals in the presence of scavengers (superoxide dismutase, 250 U/mL; catalase 500, U/mL; n=8). Pretreatment with oxygen radicals markedly reduced infarct size, from 65+/-19% of risk region in controls to 12+/-4% (P<.05). Protein kinase C inhibition significantly attenuated this effect (infarct size, 37+/-9% of risk region; P<.05 versus P/XO; P=NS versus controls). Oxygen radical-induced preconditioning was prevented by scavengers (infarct size, 55+/-14% of risk region; P<.05 versus P/XO; P=NS versus P/XO+polymyxin B). Our data show that in the absence of ischemia, exposure to low concentrations of oxygen radicals can reproduce the beneficial effects of ischemic preconditioning on infarct size and postischemic recovery of left ventricular function. Thus, oxygen radicals might be potential contributors to ischemic preconditioning.

Monoclonal antibody against tissue factor shortens tissue plasminogen activator lysis time and prevents reocclusion in a rabbit model of carotid artery thrombosis

BACKGROUND

Tissue factor (TF)-dependent activation of the coagulation is important in the pathophysiology of intravascular thrombus formation. We tested the effects of a monoclonal antibody against TF (AP-1) on lysis time induced by tissue-type plasminogen activator (TPA) and on reocclusion rate in a rabbit model of carotid artery thrombosis.

METHODS AND RESULTS

Intravascular thrombosis was obtained by placing an external constrictor around carotid arteries with endothelial injury. Carotid blood flow velocity ws measured continuously with a Doppler flow probe. Thirty minutes after thrombus formation, the rabbits received either AP-1 (0.15 mg/kg IV, n=8) or placebo (n=8). All rabbits also received TPA (80 microg/kg bolus plus 8 microg x kg(-1) x min(-1) infusion for up to 90 minutes or until reperfusion was achieved) and heparin (200 U/kg IV as a bolus). At reperfusion, TPA was discontinued, and the rabbits were followed for an additional 90 minutes. AP-1 shortened lysis time from 44+/-8 minutes (mean+/-SEM) in control rabbits to 26+/-7 minutes in AP-1 rabbits (P<.01). Reocclusion occurred in all control rabbits in 10+/-3 minutes, whereas it occurred in only two of eight AP-1 treated rabbits in 72 and 55 minutes (P<.01). No changes in prothrombin time and ex vivo platelet aggregation in response to various agonists were observed after AP-1 administration, indicating the absence of systemic effects by this antibody.

CONCLUSIONS

TF exposure and activation of the extrinsic coagulation pathway play an important role in prolonging lysis time and mediating reocclusion after thrombolysis in this model. AP-1, a monoclonal antibody against TF, might be suitable as adjunctive therapy to TPA.

[Effect of platelets and leukocytes on in vitro proliferation of muscle cells: role of platelet-derived chemical mediators]

Some evidence indicate that platelets (PLTs) and leukocytes might contribute to the development of neointimal hyperplasia following arterial injury, via release of several growth factors. To study the relative contribution of these cells and of growth factors released in consequence of activation, smooth muscle cells (SMCs), isolated from the aorta of New Zealand White rabbits, were grown in Dulbecco's medium containing 10% fetal calf serum (FCS). At 70% confluence, SMCs were made quiescent by removing FCS from the medium. Twenty-four hours later, the cells were stimulated with activated platelets, neutrophils, lymphocytes+monocytes, whole leukocytes and platelets + whole leukocytes. Then, 1 microCi of O3H-thymidine were added to SMC cultures to evaluate the degree of proliferation. Relative contribution of different PLT-derived mediators to SMC growth was evaluated by adding either ketanserin, a 5-HT2 receptor antagonist, ridogrel, a thromboxane A2 (TxA2) receptor antagonist, BN52021, a platelet activating factor (PAF) receptor antagonist, and trapidil, a platelet-derived growth factor (PDGF) receptor antagonist, or all antagonists together. SMC proliferation was significantly increased by platelet activation. This effect was reduced by adding either ketanserin, ridogrel, BN 52021 or trapidil. Neutrophils, lymphocytes + monocytes and whole leukocytes also increased SMC proliferation. Simultaneous stimulation of SMCs by platelets and whole leukocytes was associated with a significant increase in SMC proliferation as compared to platelets or leukocytes alone. Thus, TxA2, 5-HT, PAF, and PDGF all contribute to SMC proliferation in vitro. Adding all antagonist together resulted in an additive antiproliferative effect. Leukocytes are also important in SMC proliferation. Interaction between platelets and leukocytes may play a pivotal role in the modulation of this phenomenon.

[Inactivated factor VII exercises a powerful antithrombotic activity in an experimental model of recurrent arterial thrombosis]

The extrinsic coagulation pathway is activated when tissue factor (TF) is exposed as a consequence of arterial damage. TF binds to factor VII (FVII) or activated FVII (FVIIa), generating a complex that activates both FX and FIX, ultimately leading to thrombin formation. To determine whether inhibition of FVII binding to TF would result in antithrombotic effects, active site-blocked FVIIa (FVIIai) was used in a rabbit model of intravascular thrombus formation. In addition, to study the interaction between extrinsic coagulation pathway activation and platelet aggregation, in the same model of intravascular thrombus formation, recombinant human FVIIa was administered in antiplatelet-treated rabbits. Cyclic flow variations (CFVs), due to recurrent thrombus formation, were initiated by placing an external constrictor around the endothelially-injured rabbit carotid arteries (Folt's model). Carotid blood flow was measured continuously by a Doppler flow probe placed proximally to the constrictor. CFVs were induced in 29 New Zealand White rabbits. After CFVs were observed for 30 min, the animals were randomly divided in four groups: 5 animals received via a small catheter (26G) placed proximally to the stenosis, an intra-arterial infusion of human recombinant FVIIai (0.1 mg/kg/min for 10 min); 9 animals received AP-1, a monoclonal antibody against rabbit TF (0.1 mg/kg i.v. bolus); 7 animals received ridogrel, a dual thromboxane A2 synthetase inhibitor and thromboxane A2 receptor antagonist (10 mg/kg i.v. bolus); finally, 8 rabbits received aurintrycarboxilic acid (ATA), an inhibitor of platelet glycoprotein Ib/von Willebrand factor interaction (10 mg/kg i.v. bolus). FVIIai abolished CFVs in 5 of 5 animals (CFV frequency minutes 0 cycles/hour; p < 0.05; carotid blood flow velocity minutes 106 +/- 9% of the baseline values; NS vs baseline). AP-1 abolished CFVs in 7 of 9 animals (CFV frequency minutes 0 cycles/hour; p < 0.05; carotid blood flow velocity minutes 58 +/- 35% of the baseline values; NS vs baseline). Finally, in all the animals receiving ridogrel or ATA CFVs were abolished (CFV frequency 0 cycles/hour; p < 0.05 in both groups; carotid blood flow velocity, respectively 62 +/- 32 and 66 +/- 40% of the baseline values; NS vs baseline in both groups). Thirty minutes following inhibition of CFVs, in the FVIIai treated rabbits, human recombinant FVIIa was infused, via the small catheter placed proximally to the stenosis, at the dose of 0.1 mg/kg/min for 10 min. In the other three groups, FVIIa, at the same dose, was infused i.v. Infusion of FVIIa restored CFVs in all FVIIai treated animals and in 6 of 7 AP-1 treated animals, thus indicating that AP-1 and FVIIai bindings to TF was competitive and was replaced by FVIIa. Infusion of FVIIa failed to restore CFVs in ridogrel e ATA treated rabbits (1 of 7 and 0 of 8 rabbits, respectively), showing that activation of extrinsic coagulation by FVIIa was overcome by inhibition of platelet function. Activated partial thromboplastin time, and ex vivo platelet aggregation in response to ADP and thrombin, were not different after FVIIai infusion, while prothrombin time was slightly but significantly prolonged as compared to baseline values. Thus, FVII-VIIa plays an important role in initiating thrombus formation in vivo. Administration of FVIIai exerts a potent antithrombotic effects in this model without affecting systemic coagulation. In addition, in this model platelets exert an important role in arterial thrombosis, since in the presence of inhibition of platelet function, activation of the extrinsic coagulation pathway failed to restore thrombus formation.

Effects of tissue factor induced by oxygen free radicals on coronary flow during reperfusion

Tissue factor is a transmembrane protein that activates the extrinsic coagulation pathway by binding factor VII. Endothelial cells, being in contact with circulating blood, do not normally express tissue factor. Here we provide evidence that oxygen free radicals induce tissue factor messenger RNA transcription and expression of tissue factor procoagulant activity in endothelial cells in culture. Isolated, perfused rabbit hearts exposed to exogenous oxygen free radicals also showed a marked increase in tissue factor activity within the coronary circulation. Furthermore, in ex vivo and in vivo hearts subjected to ischemia and reperfusion, a condition associated with a production of oxygen free radicals in large amounts, a marked increase in tissue factor activity occurred. This phenomenon could be abolished by oxygen radical scavengers. This increase in tissue factor activity during postischemic reperfusion was accompanied by a significant decrease in coronary flow, suggesting that increase in tissue factor activity with the consequent activation of the coagulation cascade might impair coronary flow during reperfusion and possibly contribute to the occurrence of reperfusion injury.

Aurintricarboxylic acid reduces platelet deposition in stenosed and endothelially injured rabbit carotid arteries more effectively than other antiplatelet interventions

In the present study we tested the effects of different antithrombotic interventions on platelet deposition in experimentally-stenotic rabbit carotid arteries with endothelial injury. Platelet deposition, quantitated by labeling autologous platelets with 111In-oxine, was significantly reduced compared to control animals by all interventions tested, i.e., R 68070, a drug with thromboxane A2 synthase and receptor blocking properties, BN 52021, a PAF receptor antagonist, aurintricarboxylic acid (ATA), an inhibitor of platelet glycoprotein (Gp) Ib/von Willebrand factor (vWf) interaction, AZ-1, a monoclonal antibody against rabbit GP IIb/IIIa, the platelet receptor for fibrinogen, and AP-1, a monoclonal antibody against rabbit tissue factor. ATA was significantly more effective than all the other interventions in reducing platelet deposition in the stenotic vessels. We conclude that inhibition of Gp Ib/vWf interaction may be a more suitable target for antithrombotic therapy under conditions of high shear stress, like those produced in this model.

Effects of ischemia and reperfusion on cardiac tolerance to oxidative stress

Oxidative stress may affect cardiac function and metabolism. Oxidants are normally inactivated by reacting with reduced glutathione (GSH), with resulting formation and release of oxidized glutathione (GSSG). However, ischemia might affect glutathione metabolism. This might render ischemic hearts less resistant against subsequent oxidant injury during reperfusion, and it might also affect the reliability of GSSG measurements as a means to investigate oxidative stress in reperfused hearts. We compared the metabolic and functional consequences of an oxidant load in control rabbit hearts and in hearts reperfused after 30 min of normothermic total ischemia. In controls, H2O2 infusion (H2O2; 5-30 microM) induced a dose-dependent stimulation of GSSG release and a progressive impairment of cardiac function. At these doses, H2O2 challenge of postischemic hearts resulted in biochemical and functional changes identical to those observed in controls. Release of lactate dehydrogenase (LDH) and of GSH was negligible, similar in both groups. In additional experiments, infusion of H2O2 at a much higher dose (200 microM) elicited a further increase in GSSG release from both groups, although GSSG concentrations were lower in postischemic hearts. The functional effects of the 200 microM H2O2 infusion were similar in both groups, all hearts showing rapid and irreversible deterioration of function. Occurrence of irreversible cell injury was also manifested by a large release of LDH and GSH to a similar extent in both groups. These data demonstrate that cardiac tolerance toward oxidants is largely unaffected by a relatively brief episode of severe ischemia and indicate that GSSG release can be reliably used to investigate oxidative stress in reperfused hearts.

[Erythema nodosum: epidemiology, etiology, pathogenesis, clinical picture and therapy]

Erythema Nodosum (EN) is a painful nodular syndrome, most likely of immunologic origin, which involves dermis and subcutaneous tissue. Pathologic process is that of vasculitis of the small veins with inflammation of the septa of the fat lobules (septal panniculitis). It is generally agreed that EN represents a hypersensitive reaction to a variety of antigenic stimuli and thus may be observed in the course of several diseases (infections, immunopathies, malignancies) as well as during drug therapy (with halides, sulfonamides, oral contraceptives). In approximately 50 per cent of the cases an underlying etiology is not apparent (idiopathic form). The clinical picture is always that of a nonspecific systemic illness with low-grade fever (in 60%), malaise (in 67%), arthralgias (in 64%) and arthritis (in 31%), while when there is an associated illness, this may dominate the presentation. Laboratory tests show no specific abnormalities except for those related to an underlying disease. Treatment of idiopathic form includes nonsteroidal antiinflammatory agents which usually ease the discomfort. Steroids, although highly effective, are not recommended because of the benign nature of EN and the danger of disseminating an underlying disease.

Prevalence of impaired glucose tolerance, diabetes mellitus and ischemic heart disease in an Italian rural community. The Sanza Survey

Coronary heart disease rates were estimated in three groups of people participating in the Sanza Survey - newly diagnosed non insulin dependent diabetics, subjects with impaired glucose tolerance and control subjects with normal glucose tolerance. The prevalence of Minnesota-coded ECG abnormalities showed a significant gradient with an approximately twofold excess in both the newly detected diabetic and impaired glucose tolerance cases over the subjects with normal glucose tolerance. The doubling of ECG ischemic changes found in subjects with impaired glucose tolerance and diabetes mellitus appeared to operate almost equally in the absence or presence of several other recognized risk factors for coronary ischemic damage. It is concluded that a relatively low degree of glucose intolerance alone may be important in determining coronary heart disease.